What is your preference when it comes to editing/debugging large JavaScript projects, containing number of relatively big JS files?
Please list your choice, why do you like it compared to others; If it is already listed you can up vote it if you like.
There's a new IDE specifically for developing JS applications, called Cloud9. (it's still in dev, though)
Vim is my choice. IDEs cannot help you debug Javascript applications. Text editors are sufficient and fast.
But Vim's default configuration does not support Javascript well. Add-ons are prefered. You need a better indentation, Taglist for view and navigate through the outline, and custom syntax definitions for ctags (backend for Taglist) to support javascript better. To make a ctags support Javascript well, you need to tweak it yourself. There is no best solution available now. And, a little hack should be done to Taglist plugin/Vim's script for Javascript, I don't remember which of that, sorry.
MacVim, with a heavily customized .vimrc. To me, there's no IDE out there that compares to how efficient one can be in Vim, if you properly use it. This is a tad subjective, as really, IDE's and editors come down to preference. You have to find your favorite. Find an IDE/editor that you like the best, and stick with it.
I use Komodo Edit currently, since it's good for a handful of things such as pointing out some coding errors, and with the quick open extension it's really easy to get around projects. It also supports ctrl+click to jump to definitions in javascript to some extent.
However, it's not without its quirks and limitations. It's far from perfect, but it does a decent job for what I do most of the time.
Actually, I just realized now that they came out with version 6 (I was about to lament how it seemed they hadn't updated it in a while from 5.2.4). I'll have to give the new version a shot.
But yeah, I'll also +1 Cloud9 IDE; I'm very interested to see where that gets eventually.